BRITISH tourists flying to America will have to have their mobile phones and tablets charged as part of increased security measures.

American authorities said security staff at airports could ask travellers to turn on their electronic equipment to show they have power.

The measures come amid reports two terror networks are working together on a plan to blow up an airliner.

US security chiefs have said al-Qaeda are working on a plan to turn phones into bombs.

During the security examination, officers may also ask that owners power up some devices, including cell phones.

A statement by the American Transport Security Administration

A statement by the American Transport Security Administration said: "As the travelling public knows, all electronic devices are screened by security officers.

"During the security examination, officers may also ask that owners power up some devices, including cell phones.

"Powerless devices will not be permitted onboard the aircraft. The traveller may also undergo additional screening."

US officials have reportedly taken the move as a result of intelligence that al Qaeda's chief bomb maker, Ibrahim Hassan al-Asiri - who is thought to be based in Yemen - had linked up with jihadists in Syria to pass on his skills.

Sir Malcolm Rifkind, the chairman of the Intelligence and Security Committee, has said the increased airport security measures are "unavoidable".

And he warned of the dangers of "complacency" among the public in the face of the failure of the terrorists to mount any successful mass casualty attack in the UK since the 7/7 bombings in London, nine years ago today.